These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: A lymphokine distinct from interferon-gamma that activates human monocytes to kill Leishmania donovani in vitro.
    Author: Hoover DL, Finbloom DS, Crawford RM, Nacy CA, Gilbreath M, Meltzer MS.
    Journal: J Immunol; 1986 Feb 15; 136(4):1329-33. PubMed ID: 3080522.
    Abstract:
    Human interferon-gamma (IFN-gamma), a T cell lymphokine (LK), activates monocytes to kill many intra- and extracellular pathogens. In fact, previous reports assert that all activity in LK for macrophage activation is due to IFN-gamma. To test this assertion, we examined monocyte interactions with amastigotes of Leishmania donovani after treatment with recombinant DNA or affinity-purified leukocyte IFN-gamma and IFN-gamma containing LK. Cells treated with at least 200 IU/ml IFN-gamma were microbicidal for L. donovani. Analysis of IFN-gamma dose responses for induction of microbicidal activity by recombinant IFN-gamma (r-IFN-gamma) and LK, however, documented a striking difference: LK was 25-fold more efficient than r-IFN-gamma at equivalent IFN-gamma titers. This large difference suggested that monocyte activation factor(s) in LK may not be IFN-gamma. Rabbit anti-IFN-gamma completely inhibited antiviral activity in LK but did not abrogate the ability to induce monocyte cytotoxicity against leishmania. Furthermore, removal of IFN-gamma from LK by monoclonal anti-IFN-gamma affinity chromatography or by treatment with anti-IFN-gamma followed by staphylococcal protein A chromatography also did not inhibit LK activity. Fractionation of LK on Sephadex G-100 revealed two activity peaks: one in the 50,000 to 60,000 m.w. range coincident with IFN-gamma, and the other at 25,000 to 30,000 daltons with no IFN-gamma. These studies document LK physicochemically and antigenically distinct from IFN-gamma that activate monocytes to kill L. donovani. Such novel factors may have broad import for the study of macrophage-mediated host defenses and for development of immunotherapeutic regimens.
    [Abstract] [Full Text] [Related] [New Search]